This invention generally relates to the art of electrical connectors, including a method of assembling a plurality of terminals in a connector housing and facilitating the termination of the terminals to a printed circuit board.
Generally, a typical electrical connector includes some form of dielectric or insulating housing mounting a plurality of conductive terminals. For instance, the housing may be molded of plastic material and the terminals may be stamped and formed of sheet metal material. The housing has a plurality of terminal-receiving passages into which the terminals are inserted so that contact portions of the terminals are exposed for engaging the contact portions of the terminals of a complementary mating connector or other connecting device.
A typical electrical connector has a front mating end or face at which the contact portions of the terminals are exposed, and a rear terminating end or face at which terminating portions of the terminals are located. The terminal-receiving passages extend generally between the mating and terminating ends of the connector housing. The rear terminating portions of the terminals are connected to a variety of conductors ranging from discrete electrical wires to circuit traces on a printed circuit board.
A header connector is a connector of the type described above wherein the connector housing is adapted for use in conjunction with a printed circuit board. The terminals of a header connector typically are pin-type terminals or terminals which have pin portions for insertion into appropriate holes in the printed circuit board which typically is mounted at the rear terminating end or face of the connector housing. The terminal pins often are bent at right-angles for insertion into the circuit board, whereby the front mating end or face of the connector housing projects generally parallel to the circuit board. The terminal pins often are xe2x80x9ccompliantxe2x80x9d pins whereby they are forced into the holes in the printed circuit board to establish an interference or press fit within the holes.
With the ever-increasing miniaturization of electrical connectors due to the ever-increasing density of the circuits in electronic applications, a myriad of problems have been encountered in fabricating and assembling electrical connectors as described above, such as header connectors having compliant pins for insertion into holes in a printed circuit board. To begin with, because of the miniaturization of the connector assembly, itself, the conductive terminals, such as stamped and formed sheet metal terminals, are extremely small, fragile and practically impossible to maintain at proper spacing or pitch. Consequently, pin alignment plates have been used for passing the terminal pins therethrough to maintain proper relative positioning of the terminal pins. If compliant pins are used, some form of mechanical support must be provided during assembly as the pins are forced into the holes in the printed circuit board. Still further, if the compliant pins are at right angles in an angled connector assembly, support of the terminal pins is difficult and unreliable. Typical alignment plates simply do not provide sufficient retention strength to force a large number of compliant pins into the holes of the printed circuit board. Therefore, support fixtures such as steel tooling must be used to support the alignment plate and compliant pins during assembly to the printed circuit board. This metal fixture typically looks like an elongated comb for insertion between rows of the terminal pins. Unfortunately, it is desirable in many applications to stagger the terminal pins in adjacent rows thereof. Consequently, such comb-like supporting fixtures cannot even be used because the staggered pins do not provide adequate passageways for the pin projections of the comb support.
This entire intertwined series of problems has made it extremely difficult to fabricate and/or assemble header connectors, such as right-angled header connectors and particularly connectors which use compliant pins which are assembled to printed circuit boards. The present invention is directed to a unique electrical connector and a method of assembling the connector to avoid or eliminate most if not all of these numerous problems.
An object, therefore, of the invention is to provide a new and improved electrical connector assembly of the character described.
Another object of the invention is to provide a unique method of assembling the electrical connector.
In the exemplary embodiment of the invention, the electrical connector includes a dielectric connector housing, a plurality of conductive terminals and a terminal support member. The housing and the support member may be molded of plastic material, and the terminals may be stamped and formed of conductive sheet metal material. The terminals are inserted into a plurality of terminal-receiving passages in the housing, with pin portions of the terminals projecting from the housing. The pin portions of the terminals are inserted in an insertion direction into a plurality of free passages in the terminal support member from one side thereof, until enlarged retention portions of the terminals pass retention sections of a plurality of retention passages in the support member. The retention passages are immediately adjacent the free passages and are connected thereto by communication openings therebetween. The pins portions then are moved transversely of the insertion direction through the communication openings and into alignment with the retention sections in the retention passages of the support member. The pin portions then can be moved opposite the insertion direction in the retention passages until the enlarged retention portions engage the retention sections of the retention passages.
According to one aspect of the invention, the pin portions of the terminals are biased by surfaces on the support member into alignment with the free passages as the pin portions are inserted thereinto. The pins portions, thereby, are sort of spring-loaded or xe2x80x9ccockedxe2x80x9d when inserted into the free passages. Consequently, movement of the pin portions transversely of the insertion direction from the free passages through the communication openings occurs automatically by self-resiliency of the terminals. This transverse movement of the pin portions occurs as the enlarged retention portions pass an opposite side of the support member. In a preferred assembly of the electrical connector, the terminal support member is moved relative to the connector housing to effect the insertion of the pin portions of the terminals into the free passages in the support member.
According to another aspect of the invention, the pin portions of the terminals are provided with compliant distal ends which are exposed at the opposite side of the support member. A printed circuit board is mounted to the compliant distal ends when the retention portions of the terminals are in engagement with the retention sections in the retention passages of the support member. A backing support, such as a metal fixture, is provided for the support member as the printed circuit board is mounted onto the compliant distal ends of the pin portions.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.